Generally, crystalline epoxy resins have rigid or multifunctional main chain skeletons to show excellent heat resistance and are used in fields in which heat resistance reliability is required, such as the electrical and electronic fields.
However, the range of use of the crystalline epoxy resins is limited because cast molding processing, in which a liquid composition is employed, is required in some uses and the crystalline epoxy resins are used only in transfer molding or the like, in which solid material is employed.
However, the physical properties of conventional epoxy resins used in cast molding and similar liquid molding do not fully meet demands for the enhancement in the physical properties of cured products, including heat resistance that is increasingly demanded these days in adhesive, casting, sealing, molding, laminating, and similar fields. Hence, there is a growing demand for liquefaction of a crystalline multifunctional epoxy resin that imparts excellent heat resistance and similar physical properties of the cured product.
An epoxy resin is disclosed that is produced by lowering the crystallinity of a highly crystalline epoxy compound, such as tris-(2,3-epoxypropyl)-isocyanurate, through partial esterification of the epoxy groups to liquefy the epoxy compound (see Patent Document 1).
A compound including an epoxy ring bonded to a triazinetrione ring via a long chain alkylene group is disclosed (see Patent Document 2).
An epoxy compound including an epoxy ring bonded to a triazinetrione ring via a long chain alkylene group and an epoxy resin composition including the epoxy compound are disclosed (see Patent Documents 3, 4, and 5).